Power distribution unit self-identification

ABSTRACT

A power distribution discovery system includes a power distribution unit (power distribution unit) that provides electrical power to a plurality of equipment modules configured in a computing rack. The power distribution unit includes a first communication circuit coupled to a computing system. The first communication circuit communicates with a second communication circuit configured in each of the subset of equipment modules to receive identifying information associated with each of the subset of equipment modules. The computing system communicates with the first communication circuit to receive the identifying information, and outputs a report indicating the subset of equipment modules that receive electrical power from the power distribution unit. The received identifying information indicates those equipment modules that receive electrical power from the power distribution unit.

TECHNICAL FIELD

Aspects of the present disclosure relate to computing devices and, inparticular, to a power distribution unit discovery system fordiscovering equipment modules in a computing rack.

BACKGROUND

Many of today's modern computing systems are provided as data centerswhere relatively large quantities of equipment modules are implementedfor use as storage systems, telecommunications systems, andcomputationally intensive processing systems. To house such equipmentmodules, computing racks have been developed. Electrical power for thesecomputing devices is typically provided by a power distribution unit inwhich electrical power from only one or a few sources can be distributedamong the multiple equipment modules. In many cases, a computing rackmay be configured with multiple power distribution units for variousreasons, such as redundancy, power sharing, computing rack wiringorganization, and the like. It is quite difficult to determine whichpower distribution unit is supplying electrical power to each equipmentmodule due to the numerous equipment modules in a rack and theassociated cabling.

BRIEF SUMMARY

A first embodiment disclosed herein is a power distribution discoverysystem for discovering equipment modules comprising a power source and apower distribution unit with a plurality of outlets, each of theplurality of outlets being configured to transfer, from the powersource, electrical power to an equipment module of a plurality ofequipment modules, each equipment module of the plurality of equipmentmodules being positioned in a computing rack and connected to a one ofthe plurality of outlets. The power distribution unit comprises a firstcommunication circuit that facilitates: communication with a pluralityof second communication circuits in each of the plurality of equipmentmodules, and communication with a computing device. The powerdistribution unit further comprises: one or more data processors and anon-transitory computer readable storage medium containing instructionsthat when executed on the one or more data processors, cause the one ormore data processors to perform actions including: receiving, via thefirst communication circuit, and from each second communication circuitof the plurality of second communication circuits, an identifyinginformation for an equipment module of the plurality of equipmentmodules; and generating a report that includes the identifyinginformation. The first embodiment of the power distribution discoverysystem for discovering equipment modules can further include actionssending, via the first communication circuit and to each secondcommunication circuit of the plurality of second communication circuits,a request for identifying information for an equipment module connectedto an outlet of the plurality of outlets, the plurality of equipmentmodules including the equipment module and further including thesending, via the first communication circuit and to each secondcommunication circuit of the plurality of second communication circuits,a request for identifying information for an equipment module connectedto an outlet of the plurality of outlets, the plurality of equipmentmodules including the equipment module happens at pre-determinedintervals in another embodiment. The first embodiment of the powerdistribution discovery system for discovering equipment modules canfurther include the actions of receiving, via the first communicationcircuit, and from each second communication circuit of the plurality ofsecond communication circuits, the identifying information for anequipment module of the plurality of equipment modules happens atpre-determined intervals or receiving, from a computing device, arequest for identifying information and sending the report to thecomputing device. And in further embodiments actions can includereceiving, from a computing device, a request for identifyinginformation; and sending the report to the computing device. A furtheraddition to the first embodiment is wherein the identifying informationis transmitted through an electrical cable that electrically couples thepower distribution unit to the equipment modules.

A second embodiment disclosed herein is a non-transitory,computer-readable medium comprising instructions that, when executed byone or more processors, causes the one or more processors to performoperations to discover equipment modules comprising receiving, via afirst communication circuit of a power distribution unit, and from eachsecond communication circuit of a plurality of second communicationcircuits of a plurality of equipment modules, an identifying informationfor an equipment module of a plurality of equipment modules. The powerdistribution unit comprises: a plurality of outlets, each of theplurality of outlets being configured to transfer, from a power source,electrical power to an equipment module of the plurality of equipmentmodules, each equipment module of the plurality of equipment modulesbeing positioned in a computing rack and connected to an outlet of theplurality of outlets: And the one or more processors to performoperations to discover equipment modules further comprising generating areport that includes the identifying information. And further sending,via the first communication circuit and to each second communicationcircuit of the plurality of second communication circuits, a request foridentifying information for an equipment module connected to an outletof the plurality of outlets, the plurality of equipment modulesincluding the equipment module and wherein the sending, via the firstcommunication circuit and to each second communication circuit of theplurality of second communication circuits, a request for identifyinginformation for an equipment module connected to an outlet of theplurality of outlets, the plurality of equipment modules including theequipment module happens at pre-determined intervals. And anotherextension of the embodiment of the non-transitory, computer-readablemedium comprising instructions that, when executed by one or moreprocessors, causes the one or more processors to perform operations todiscover equipment modules, wherein the receiving, via the firstcommunication circuit, and from each second communication circuit of theplurality of second communication circuits, the identifying informationfor an equipment module of the plurality of equipment modules happens atpre-determined intervals. Another embodiment further comprisesreceiving, from a computing device, a request for identifyinginformation; and sending the report to the computing device. Anotherembodiment further comprises receiving, from a computing device, arequest for identifying information; and sending the report to thecomputing device. An additional embodiment is wherein the identifyinginformation is transmitted through an electrical cable that electricallycouples the power distribution unit to the equipment modules.

And yet a third embodiment disclosed herein is a power distributiondiscovery method for discovering equipment modules, the methodcomprising receiving, via a first communication circuit of a powerdistribution unit, and from each second communication circuit of aplurality of second communication circuits of a plurality of equipmentmodules, an identifying information for an equipment module of aplurality of equipment modules. And wherein the power distribution unitcomprises a plurality of outlets, each of the plurality of outlets beingconfigured to transfer, from a power source, electrical power to anequipment module of the plurality of equipment modules, each equipmentmodule of the plurality of equipment modules being positioned in acomputing rack and connected to an outlet of the plurality of outlets.And further including the action of generating a report that includesthe identifying information. An extension of the third embodimentfurther comprises sending, via the first communication circuit and toeach second communication circuit of the plurality of secondcommunication circuits, a request for identifying information for anequipment module connected to an outlet of the plurality of outlets, theplurality of equipment modules including the equipment module. The thirdembodiment can also the sending, via the first communication circuit andto each second communication circuit of the plurality of secondcommunication circuits, a request for identifying information for anequipment module connected to an outlet of the plurality of outlets, theplurality of equipment modules including the equipment module happens atpre-determined intervals. Another extension to the third embodimentwherein the receiving, via the first communication circuit, and fromeach second communication circuit of the plurality of secondcommunication circuits, the identifying information for an equipmentmodule of the plurality of equipment modules happens at pre-determinedintervals. The third embodiment may also further comprise receiving,from a computing device, a request for identifying information andsending the report to the computing device or receiving, from acomputing device, a request for identifying information and sending thereport to the computing device.

BRIEF DESCRIPTION OF THE DRAWINGS

The various features and advantages of the technology of the presentdisclosure will be apparent from the following description of particularembodiments of those technologies, as illustrated in the accompanyingdrawings. It should be noted that the drawings are not necessarily toscale; however the emphasis instead is being placed on illustrating theprinciples of the technological concepts. Also, in the drawings the likereference characters refer to the same parts throughout the differentviews. The drawings depict only typical embodiments of the presentdisclosure and, therefore, are not to be considered limiting in scope.

FIG. 1A illustrates an example power distribution discovery system thatmay be implemented in a computing rack according to one embodiment ofthe present disclosure.

FIG. 1B illustrates an example power distribution unit (powerdistribution unit) that has been removed from the computing rack toreveal several of its features according to one embodiment of thepresent disclosure.

FIG. 2A illustrates an example wiring diagram of the power distributionunit of FIG. 1B according to one embodiment of the present disclosure.

FIG. 2B illustrates an example equipment module that may be used withthe power distribution discovery system according to one embodiment ofthe present disclosure.

FIG. 3 illustrates an example power distribution unit communicationcircuit according to one embodiment of the present disclosure.

FIG. 4 illustrates a block diagram of an example computing device thatmay be used to execute a power distribution discovery applicationaccording to one embodiment of the present disclosure.

FIG. 5 illustrates an example process that may be performed by theapplication according to one embodiment of the present disclosure.

FIG. 6 illustrates an example computer device according to oneembodiment of the present disclosure.

DETAILED DESCRIPTION

Embodiments of the present disclosure provide a power distributiondiscovery system that discovers which equipment modules are wired toreceive electrical power from each of one or more power distributionunits configured in a computing rack. Modern computing rack designsoften utilize multiple power distribution units in each computing rackfor various reasons that may include, for example, power redundancy,power sharing, and/or for efficient organization of the electrical powercabling in the computing rack. Nevertheless, when these computing racksare implemented with multiple power distribution units, diagnosing powerproblems often becomes difficult due mainly to the difficulty inidentifying which power distribution unit each equipment module iscoupled to and receiving power from. Embodiments of the presentdisclosure provide a solution to this problem by including a firstcommunication circuit in each power distribution unit that communicateswith complementary second communication circuits configured in eachequipment module using the power cable coupled between each equipmentmodule and the power distribution unit as a communication medium.Through the circuits, each power distribution unit may discover thoseequipment modules to which it is connected and report such findings sothat users may readily ascertain which equipment modules may bereceiving electrical power from each power distribution unit configuredin the computing rack.

FIG. 1A illustrates an example power distribution discovery system 100that may be implemented in a computing rack 102 according to oneembodiment of the present disclosure. The computing rack 102 generallyincludes a box-like structure that forms an enclosure 104 for theplacement of one or more equipment modules 106. As will be described indetail herein below, the system 100 includes one or more powerdistribution units 108 that receives identifying signals from eachequipment module 106 to which it is coupled and transmits informationassociated with the signals to a computing device 110, which in turn,displays the information on a user interface 112 for view by a user.Using this information, the user may ascertain which power distributionunit 108 from among multiple power distribution units 108 is poweringwhich equipment modules 106.

The computing rack 102 may be any suitable type. Examples of suchcomputing racks include those that are generally referred to as 19-inchracks or 23-inch racks. The 19-inch racks may be constructed accordingto various specifications, such as the Electronics Industries Alliance310-D (EIA 310D) specification. Although 23-inch racks are often used bythe telecommunication industry, 19-inch racks may be relatively morecommon with other computing system implementations. In general, thesecomputing racks typically comprise a structure in which one or moreequipment modules 106 may be mounted.

The computing rack 102 can have any shape or size. The computing rackprovides for the configuration of a relatively large number of equipmentmodules in a small volume. To supply electrical power to these equipmentmodules, one or more power distribution units may be provided. Problemsarise, however, in that when multiple power distribution units 108 areused, the relatively large quantity of modules results in clutteredwiring within the computing rack such that isolating each equipmentmodule according to the power distribution unit that it is powered byoften becomes difficult. Many time equipment modules 106 have poweruncoupled during the isolation process when it is undesirable to do so.Such undesirable interruption can cause critical processinginterruptions of critical tasks—often with dire consequences.Embodiments of the present disclosure provide a solution to this problemby identifying those equipment modules 106 that are coupled to, andreceive electrical power, from which power distribution unit 108 anddisplay the information for view by a user.

The computing device 110 is coupled to each power distribution unit 108by one or means of communication 150 including direct wired by Ethernet,USB, or other wired connection or by a wireless connection including anetwork. Wireless connections can include Bluetooth and IR, but are notso limited. The wireless network can include, for example, the Internet,an intranet, a secure network, a virtual private network, a local areanetwork, a wide area network, or a cellular network, but is not solimited. The computing device 110 has a display 108 and an input device114. The computing device is described in more detail in FIG. 4 below.

FIG. 1B illustrates an example power distribution unit 108 that has beenremoved from the computing rack 102 to reveal several of its featuresaccording to one embodiment of the present disclosure. In general, thepower distribution unit 108 comprises an elongated channel 116, or othersimilar structure, on which multiple outlets 118 may be configured.Additionally, the elongated channel 116 may be used to house electricalcables that electrically couple the outlets 118 thorough external cable119 to a suitable power source 120. For example, the outlets 118 mayinclude a National Electrical Manufacturers Association (NEMA) 5-15grounded (Type B) connector as specified by the IEC although any typemay be used. Although the power distribution unit 108 is describedherein as including an elongated channel 116, it should be understoodthat the power distribution unit 108 may have any shape and/or sizewithout deviating from the spirit and scope of the present disclosure.

FIG. 2A illustrates an example wiring diagram of the power distributionunit 108 of FIG. 1B according to one embodiment of the presentdisclosure. The power distribution unit 108 generally includes anelectrical cable 202 that electrically couples the outlets 118 to anisolator 204 and then, indirectly, to a power source 120 using externalcable 119. According to the teachings of the present disclosure, thepower distribution unit 108 also includes a power distribution unitcommunication circuit 206 that can be coupled to the electrical cable202, and is configured to receive identifying signals from eachequipment module 106 to which it is connected. The power distributionunit communication circuit 206 may be coupled to the electrical cable202 in any suitable manner. In one embodiment, the power distributionunit communication circuit 206 may be electrically coupled to theelectrical cable 202, such as connected by a first signal wire to a‘neutral’ wire of the electrical cable 202, and connecting a secondsignal wire to a ‘hot’ wire of the electrical cable 202. In anotherembodiment, the power distribution unit communication circuit 206 may bemagnetically coupled to the electrical cable such that the powerdistribution unit communication circuit 206 may detect the identifyingsignal via magnetic flux variations generated by the electrical cable202. Isolator 204 is an isolation circuit that prevents communicationsover the electrical cable 202 from leaving the power distribution unit108 via the external cable 119. Without Isolator 204, the identifyingsignals would continue to be propagated on cable 119. The powerdistribution unit communication circuit 206 also facilitates coupling toa computing device 110 via connection 150 by wired or wirelesscommunications mechanisms.

FIG. 2B illustrates an example equipment module 106 that may be usedwith the system 100 according to one embodiment of the presentdisclosure. The equipment module 106 may be configured for placement inthe computing rack 102 and may be referred to as a rack-mount module,rack mountable equipment, a rack-mount instrument, and the like. Theequipment module 106 may be any type that is mountable and/or supportedin the computing rack 102. Examples of such equipment modules includecomputing devices, blade servers, routers, switches, storage units(e.g., memory, hard disk drives, flash storage, etc.), power supplyunits, and the like.

In general, the equipment module 106 includes equipment module circuitry210 to provide one or more functions such as described above. Theequipment module 106 may also include a power supply 212 or othersuitable power conversion system, for converting line power providedfrom the power distribution unit 108 to which it is connected to a formsuitable for use by the equipment module circuitry 210. The power supply212 may be electrically coupled to the power distribution unit 108through the electrical cable 214 using a power connector 216, which hascontacts that are configured to be electrically coupled to complementarycontacts configured on an outlet 118 on the power distribution unit 108,and is shown by the connection cable 250 shown as a dotted line betweenoutlet 118 and power connector 216. According to the teachings of thepresent disclosure, the equipment module 106 also includes an equipmentmodule communication circuit 218 that is coupled to the electrical cable214, and configured to generate the identifying signal that is to bereceived by the power distribution unit communication circuit 206configured in the power distribution unit 108. The equipment modulecommunication circuit 218 may be coupled to the electrical cable 214 inany suitable manner. In one embodiment, the equipment modulecommunication circuit 218 may be electrically coupled to the electricalcable, such as by connecting a first signal wire to a ‘neutral’ wire ofthe electrical cable 214, and connecting a second signal wire to a ‘hot’wire of the electrical cable 214. In another embodiment, the equipmentmodule communication circuit 218 may be magnetically coupled to theelectrical cable such that the power distribution unit communicationcircuit 206 may detect the identifying signal via magnetic fluxvariations generated by the electrical cable 214. Equipment modulecommunication circuit 218 may also include any other type ofcommunication mechanism to facilitate any type of wired or wirelesscommunication.

In general, the equipment module communication circuit 218 and powerdistribution unit communication circuit 206 communicate with one anotherusing the electrical cable 214 of the equipment module 106, connectioncable 250, and the electrical cable 202 of the power distribution unit108 as a transmission medium. Thus, the equipment module communicationcircuit 218 will only receive identifying signals from equipment modules106 to which it's connected and receiving electrical power from. Theequipment module communication circuit 218 and power distribution unitcommunication circuit 206 may communicate with one another using anysuitable protocol. In one embodiment, the equipment module communicationcircuit 218 and power distribution unit communication circuit 206 maycommunicate using an X10 power line communication protocol. In anotherembodiment, the equipment module communication circuit 218 and powerdistribution unit communication circuit 206 may communicate using aPLC-BUS communication protocol. Any communication mechanism between theequipment module 106 and the power distribution module 108 iscontemplated by the present disclosure.

Using such an arrangement of an equipment module communication circuit218 configured in each equipment module 106 and a power distributionunit communication circuit 206 configured in the power distribution unit108, the system 100 may identify which equipment module 106 is poweredby each power distribution unit 108 in the computing rack 102. Forexample, each equipment module communication circuit 218 may generate aserial number of the associated equipment module 106 at ongoingintervals (e.g., periodic intervals) that may be received and processedby the power distribution unit communication circuit 206. As anotherexample, each equipment module communication circuit 218 may beresponsive to a query signal transmitted by the power distribution unitcommunication circuit 206 to transmit the serial number of itsassociated equipment module 106 to the power distribution unitcommunication circuit 206.

Although the power distribution unit 108 of FIG. 2A and the equipmentmodule 106 of FIG. 2B illustrate an example power distribution unit 108and equipment module 106 that may be used with the system 100, it shouldbe understood that other power distribution units or equipment modulesmay have additional, fewer, or different components than what is shownherein without deviating from the spirit and scope of the presentdisclosure. For example, the power distribution unit 108 may includeother components such as one or more switches for selectively applyingelectrical power to certain ones of the outlets 118 configured on thepower distribution unit 108. As another example, the equipment module106 may include other components other than circuitry, such as one ormore lamps, or other light generating devices, for illuminating certainportions of the computing rack or for generating a signal to be receivedby the user. Such an equipment module 106 may, or may not have, anycircuitry 210 such as is described above with respect to FIG. 2B.

FIG. 3 illustrates an example power distribution unit communicationcircuit 206 according to one aspect of the present disclosure. The powerdistribution unit communication circuit 206 includes one or moreprocessors 304 and memory 306 that stores a modem interface 308 and acommunication algorithm 310 that are executed by the processors 304. Themodem interface 308 receives identifying information from a modem 312that is in communication with the electrical cable 202 of its respectivepower distribution unit 108, processes the information, and thentransfers the processed information to the communication algorithm 310that transmits the information, through the modem interface 308 to themodem 312 to the computing device 110 using means of communication 150.

Although the power distribution unit communication circuit 206 is shownand described as a computer-based design incorporating instructionsstored in a memory 306 and executed by a processor 304, it should beunderstood that the power distribution unit communication circuit 206may be embodied in other specific forms, such as using discrete and/orintegrated analog circuitry, field programmable gate arrays (FPGAs),application specific integrated circuitry (ASICs), or any combinationthereof. Communication circuit 206 also comprises the necessarycircuitry to communicate with the computing device 110 using means ofcommunication 150.

Referring now to FIG. 4, a block diagram of an example powerdistribution unit distribution discovery application 402 executed on thecomputing device 110 is depicted according to one aspect of the presentdisclosure. The power distribution unit distribution discoveryapplication 402 is stored in a memory (e.g., computer readable media)404 and executed on a processing system 406 of the computing device 110.The computing device 110 may include any type of computing system, suchas one or more computing systems in communication with one another, oneor more personal computers, one or more mobile computers and/or othermobile devices.

The computing device 110 also includes a user interface 112 (e.g., agraphical user interface (GUI)) displayed on a display 108, such as acomputer monitor, for displaying data. The computing device 110 may alsoinclude an input device 114, such as a keyboard or a pointing device(e.g., a mouse, trackball, pen, or touch screen) to enter data into orinteract with the user interface 112. According to one aspect, the powerdistribution unit distribution discovery application 402 includesinstructions or modules that are executable by the processing system 406as will be described in detail herein below.

The memory 404 includes volatile media, nonvolatile media, removablemedia, non-removable media, and/or another available medium. By way ofexample and not limitation, non-transitory computer readable mediumcomprises computer storage media, such as non-transient storage memory,volatile media, nonvolatile media, removable media, and/or non-removablemedia implemented in a method or technology for storage of information,such as computer readable instructions, data structures, programmodules, or other data.

A user interface module 412 communicates with the user interface 112, orother remotely configured computing device to facilitate receipt ofinput data and/or output data from or to a user (e.g., an administratorof the computing rack 102), respectively. The user interface module 412may display information to, and receive user information from the userin any suitable form, such as via a graphical user interface (GUI) or acommand line interface (CLI). For example, the user interface module 412may display a list of the equipment modules 106 that are powered by oneor more power distribution units 108 on a display of the computingdevice 110. As another example, the user interface module 412 mayreceive user input for initiating a discovery process, or for receivinguser input for manipulating one or more settings of how the system 100operates, such as whether the equipment module communication circuit 218transmit the identifying information periodically, or whether theequipment modules 106 transmit the identifying information in responseto a request from the power distribution unit communication circuit 206.

A computing rack management application interface module 414 provides aninterface to a computing rack management application that manages theoperation of the computing rack 102. For example, the computing rackmanagement application interface module 414 may communicate with thecomputing rack management application to receive a request forassociating those equipment modules 106 that receive electrical powerfrom a particular power distribution unit 108 and in response, generatea request to be transmitted to the power distribution unit communicationcircuit 206 of that power distribution unit 108 for obtaining therequested information. The computing rack management application may beany suitable type that manages the operation of the computing rack 102,which may also include other computing racks, such as a data center thatoften employs the use of equipment modules 106 that may be distributedover multiple computing racks. In this manner, the system 100 may beused to provide equipment module/power distribution unit associationinformation that may be useful for management operations of thecomputing rack management application.

A power distribution unit communication circuit control module 416manages the operation of the power distribution unit communicationcircuit 206 configured in each power distribution unit 108 in thecomputing rack 102. Additionally, the power distribution unitcommunication circuit control module 416 may also manage the operationof each or certain power distribution unit communication circuits 206configured in each equipment module 106 in the computing rack 102. Forexample, the power distribution unit communication circuit controlmodule 416 may communicate with the power distribution unitcommunication circuit 206 to issue an instruction to the equipmentmodule communication circuits 218 to which it is connected, to adjustits operation (e.g., change from transmitting its identifyinginformation upon request to periodically transmitting its identifyinginformation, change an elapsed period of time between each transmission,etc.). In one embodiment, the operation of certain ones of the equipmentmodule communication circuits 218 may be adjusted. In other embodiments,the operation of certain ones of the equipment module communicationcircuits 218 may be set during manufacture such that they are notadjustable by the power distribution unit communication circuit controlmodule 416. In yet another embodiment, certain ones of the equipmentmodule communication circuits 218 may be adjusted manually by the user.For example, certain equipment module communication circuits 218 mayinclude one or more switches that may be switched on or off for settinghow they operated in the system 100.

It should be appreciated that the modules described herein are providedonly as examples and that the power distribution unit distributiondiscovery application 402 may have different modules, additionalmodules, or fewer modules than those described herein. For example, oneor more modules as described in FIG. 4 may be combined into a singlemodule. As another example, certain modules described herein may beencoded on, and executed on other computing systems, such as on one thatis used to execute the computing rack management application.

FIG. 5 illustrates an example process that may be performed by theapplication 402 according to one embodiment of the present disclosure.Initially, one or more of the power distribution units 108 along withmultiple equipment modules 106 are configured in the computing rack 102.In some cases, in which the operation of the equipment modulecommunication circuit 218 in certain equipment modules 106 are setmanually (e.g., using one or more control switches on the equipmentmodule communication circuit), the operation of the equipment modulecommunication circuit 218 in those equipment modules 106 may be set whenconfigured in the computing rack 102.

At block 502, the application 402 communicates with the powerdistribution unit communication circuit 206 in each power distributionunit 108 to select the operational mode of the system 100. For example,the application 402 may issue an instruction to the equipment modulecommunication circuit 218 to periodically receive identifyinginformation from the equipment module communication circuit 218 of eachequipment module 106 to which it is connected. Upon receipt of thisinstruction, the equipment module communication circuit 218 may thenissue a request to the equipment module communication circuit 218 ofeach equipment module 106 to which it is connected to periodicallytransmit its identifying information. The request may also include otheroperational instructions, such as an elapsed period of time between eachtransmission. In yet another embodiment, the each equipment module 106can be configured to transmit identifying information at pre-determinedintervals in the absence of a request from the power distribution unit108.

At block 504, the application 402 issues a request to discover thoseequipment modules 106 that are coupled to (e.g., powered by) the powerdistribution unit 108. In one embodiment, if the system 100 has beenconfigured so that the equipment module communication circuits 218periodically transmit their identifying information, then the powerdistribution unit communication circuit 206 may return the equipmentmodule identification records 420 stored in its memory. However inanother embodiment, if the system 100 has been configured so that theequipment module communication circuits 218 transmit their identifyinginformation upon request, then the power distribution unit communicationcircuit 206 may issue a request to all equipment module communicationcircuits 218 to transmit their identifying information. Upon receipt ofthe identifying information, the identifying information may beforwarded to the application 402.

At block 505, the power distribution unit 108 receives a request fromthe computing device 110 to discover the equipment modules 106 connectedto outlets 118. This request could be received via a wired or wirelessconnection using any one of a variety of communication protocols. Inanother embodiment the power distribution unit 108 could receive arequest from computing device 110 to determine if an equipment module106 associated with a particular identification is using on outlet 118on the power distribution unit 108.

At block 506, the application 402 issues a request to the powerdistribution unit communication circuit 206 to discover the equipmentmodules that it is coupled to. Thereafter at block 508, the application402 receives the identifying information from the power distributionunit communication circuit 206. At block 509, the power distributionunit 108 generates a report for the received identifying information forthe plurality of equipment modules 106 connected to the plurality ofoutlets 118 that is compatible with user interface 112 for view by auser of computing device 110. At block 510 the power distribution unit108 sends the report to the computing device 110.

In one embodiment, the blocks described above may be initiated by acomputing rack management application that controls the operation of theequipment modules 106 in the computing rack. For example, if a poweroutage occurs to certain equipment modules 106 in the computing rack102, a user of the computing rack management application may enter userinput for instructing the application 402 to perform a discovery processto determine whether those equipment modules 106 that have experiencedthe power outage are powered by the subject power distribution unit 108.As another example, the user of the computing rack managementapplication may instruct the application to perform a discovery processto identify those equipment modules 106 that receive electrical powerfrom the power distribution unit 108 to ensure that the powerdistribution unit 108 is not being overloaded with too many devices. Asyet another example, the user of the computing rack managementapplication may, using user input, instruct the application to perform adiscovery process for identifying the equipment modules 106 that receiveelectrical power from the power distribution unit 108 for performing oneor more diagnostics processes on the equipment modules 106 of thecomputing rack 102 (e.g., fault isolation, mis-wiring of certainequipment modules, etc.).

The process described above may be repeated to identify those equipmentmodules 106 that received electrical power from the power distributionunit 108, or to identify those equipment modules 106 that receiveelectrical power from other power distribution units 108. Nevertheless,when use of the application 402 is no longer needed or desired, theprocess ends.

Although FIG. 5 describes one example of a process that may be performedby the application 402, it should be understood that other processes maybe performed without departing from the spirit or scope of the presentdisclosure. For example, the process described above may includeadditional, fewer, or different actions than what is described herein.As another example, the communication device 206 in the powerdistribution unit 108 may be configured to transmit its identifyinginformation, while the communication device 218 in the equipment modules106 may be configured to receive the identifying information. Therefore,in such a case, the application 402 may communicate with thecommunication devices 218 in each equipment modules 106 to determinewhich power distribution unit 108 that is receiving electrical powerfrom.

For example, FIG. 6 is a block diagram illustrating an example ofcomputing device 110 which may be used in implementing the embodimentsof the present disclosure. The computer device 110 includes one or moreprocessors 602-606. Processors 602-606 may include one or more internallevels of cache (not shown) and a bus controller or bus interface unitto direct interaction with the processor bus 612. Processor bus 612,also known as the host bus or the front side bus, may be used to couplethe processors 602-606 with the system interface 614. System interface614 may be connected to the processor bus 612 to interface othercomponents of the computing device 110 with the processor bus 612. Forexample, system interface 614 may include a memory controller 618 forinterfacing a main memory 616 with the processor bus 612. The mainmemory 616 typically includes one or more memory cards and a controlcircuit (not shown). System interface 614 may also include aninput/output (I/O) interface 620 to interface one or more I/O bridges orI/O devices with the processor bus 612. One or more I/O controllersand/or I/O devices may be connected with the I/O bus 626, such as I/Ocontroller 628 and I/O device 660, as illustrated.

I/O device 660 may also include an input device (not shown), such as analphanumeric input device, including alphanumeric and other keys forcommunicating information and/or command selections to the processors602-606. Another type of user input device includes cursor control, suchas a mouse, a trackball, or cursor direction keys for communicatingdirection information and command selections to the processors 602-606and for controlling cursor movement on the display device.

Computing device 110 may include a dynamic storage device, referred toas main memory 616, or a random access memory (RAM) or othercomputer-readable devices coupled to the processor bus 612 for storinginformation and instructions to be executed by the processors 602-606.Main memory 616 also may be used for storing temporary variables orother intermediate information during execution of instructions by theprocessors 602-606. Computing device 110 may include a read only memory(ROM) and/or other static storage device coupled to the processor bus612 for storing static information and instructions for the processors602-606. The system set forth in FIG. 6 is but one possible example of acomputer system that may employ or be configured in accordance withaspects of the present disclosure.

According to one embodiment, the above techniques may be performed bycomputer computing device 110 in response to processor 602-606 executingone or more sequences of one or more instructions contained in mainmemory 616. These instructions may be read into main memory 616 fromanother machine-readable medium, such as a storage device. Execution ofthe sequences of instructions contained in main memory 616 may causeprocessors 602-606 to perform the process blocks described herein. Inalternative embodiments, circuitry may be used in place of or incombination with the software instructions. Thus, embodiments of thepresent disclosure may include both hardware and software components.

A computer readable medium includes any mechanism for storing ortransmitting information in a form (e.g., software, processingapplication) readable by a machine (e.g., a computer). Such media maytake the form of, but is not limited to, non-volatile media and volatilemedia. Non-volatile media includes optical or magnetic disks. Volatilemedia includes dynamic memory, such as main memory 616. Common forms ofmachine-readable medium may include, but is not limited to, magneticstorage medium (e.g., hard disk drive); optical storage medium (e.g.,CD-ROM); magneto-optical storage medium; read only memory (ROM); randomaccess memory (RAM); erasable programmable memory (e.g., EPROM andEEPROM); flash memory; or other types of medium suitable for storingelectronic instructions.

Embodiments of the present disclosure include various operations orblocks, which are described in this specification. The blocks may beperformed by hardware components or may be embodied inmachine-executable instructions, which may be used to cause ageneral-purpose or special-purpose processor programmed with theinstructions to perform the blocks. Alternatively, the blocks may beperformed by a combination of hardware, software and/or firmware.

It is believed that the present disclosure and many of its attendantadvantages will be understood by the foregoing description, and it willbe apparent that various changes may be made in the form, construction,and arrangement of the components without departing from the disclosedsubject matter or without sacrificing all of its material advantages.The form described is merely explanatory, and it is the intention of thefollowing claims to encompass and include such changes.

While the present disclosure has been described with reference tovarious embodiments, it will be understood that these embodiments areillustrative and that the scope of the disclosure is not limited tothem. Many variations, modifications, additions, and improvements arepossible. More generally, embodiments in accordance with the presentdisclosure have been described in the context of particularimplementations. Functionality may be separated or combined in blocksdifferently in various embodiments of the disclosure or described withdifferent terminology. These and other variations, modifications,additions, and improvements may fall within the scope of the disclosureas defined in the claims that follow.

The description above includes example systems, methods, techniques,instruction sequences, and/or computer program products that embodytechniques of the present disclosure. However, it is understood that thedescribed disclosure may be practiced without these specific details.

In the present disclosure, the methods disclosed may be implemented assets of instructions or software readable by a device. Further, it isunderstood that the specific order or hierarchy of blocks in the methodsdisclosed are instances of example approaches. Based upon designpreferences, it is understood that the specific order or hierarchy ofblocks in the method can be rearranged while remaining within thedisclosed subject matter. The accompanying method claims presentelements of the various blocks in a sample order, and are notnecessarily meant to be limited to the specific order or hierarchypresented.

The described disclosure may be provided as a computer program product,or software, that may include a machine-readable medium having storedthereon instructions, which may be used to program a computer system (orother electronic devices) to perform a process according to the presentdisclosure. A machine-readable medium includes any mechanism for storinginformation in a form (e.g., software, processing application) readableby a machine (e.g., a computer). The machine-readable medium mayinclude, but is not limited to, magnetic storage medium (e.g., hard diskdrive), optical storage medium (e.g., CD-ROM); magneto-optical storagemedium, read only memory (ROM); random access memory (RAM); erasableprogrammable memory (e.g., EPROM and EEPROM); flash memory; or othertypes of medium suitable for storing electronic instructions.

For example, FIG. 6 is a block diagram illustrating an example of a hostor computer computing device 110 which may be used in implementing theembodiments of the present disclosure. The computer system (system)includes one or more processors 602-606. Processors 602-606 may includeone or more internal levels of cache (not shown) and a bus controller orbus interface unit to direct interaction with the processor bus 612.Processor bus 612, also known as the host bus or the front side bus, maybe used to couple the processors 602-606 with the system interface 614.System interface 614 may be connected to the processor bus 612 tointerface other components of the computing device 110 with theprocessor bus 612. For example, system interface 614 may include amemory controller 618 for interfacing a main memory 616 with theprocessor bus 612. The main memory 616 typically includes one or morememory cards and a control circuit (not shown). System interface 614 mayalso include an input/output (I/O) interface 620 to interface one ormore I/O bridges or I/O devices with the processor bus 612. One or moreI/O controllers and/or I/O devices may be connected with the I/O bus626, such as I/O controller 628 and I/O device 660, as illustrated.

I/O device 660 may also include an input device (not shown), such as analphanumeric input device, including alphanumeric and other keys forcommunicating information and/or command selections to the processors602-606. Another type of user input device includes cursor control, suchas a mouse, a trackball, or cursor direction keys for communicatingdirection information and command selections to the processors 602-606and for controlling cursor movement on the display device.

Computing device 110 may include a dynamic storage device, referred toas main memory 616, or a random access memory (RAM) or othercomputer-readable devices coupled to the processor bus 612 for storinginformation and instructions to be executed by the processors 602-606.Main memory 616 also may be used for storing temporary variables orother intermediate information during execution of instructions by theprocessors 602-606. Computing device 110 may include a read only memory(ROM) and/or other static storage device coupled to the processor bus612 for storing static information and instructions for the processors602-606. The system set forth in FIG. 6 is but one possible example of acomputer system that may employ or be configured in accordance withaspects of the present disclosure.

According to one embodiment, the above techniques may be performed bycomputer computing device 110 in response to processor 602-606 executingone or more sequences of one or more instructions contained in mainmemory 616. These instructions may be read into main memory 616 fromanother machine-readable medium, such as a storage device. Execution ofthe sequences of instructions contained in main memory 616 may causeprocessors 602-606 to perform the process blocks described herein. Inalternative embodiments, circuitry may be used in place of or incombination with the software instructions. Thus, embodiments of thepresent disclosure may include both hardware and software components.

Embodiments of the present disclosure include various operations orblocks, which are described in this specification. The blocks may beperformed by hardware components or may be embodied inmachine-executable instructions, which may be used to cause ageneral-purpose or special-purpose processor programmed with theinstructions to perform the blocks. Alternatively, the blocks may beperformed by a combination of hardware, software and/or firmware.

It is believed that the present disclosure and many of its attendantadvantages will be understood by the foregoing description, and it willbe apparent that various changes may be made in the form, construction,and arrangement of the components without departing from the disclosedsubject matter or without sacrificing all of its material advantages.The form described is merely explanatory, and it is the intention of thefollowing claims to encompass and include such changes.

While the present disclosure has been described with reference tovarious embodiments, it will be understood that these embodiments areillustrative and that the scope of the disclosure is not limited tothem. Many variations, modifications, additions, and improvements arepossible. More generally, embodiments in accordance with the presentdisclosure have been described in the context of particularimplementations. Functionality may be separated or combined in blocksdifferently in various embodiments of the disclosure or described withdifferent terminology. These and other variations, modifications,additions, and improvements may fall within the scope of the disclosureas defined in the claims that follow.

A number of variations and modifications of the disclosed embodimentscan also be used. Specific details are given in the above description toprovide a thorough understanding of the embodiments. However, it isunderstood that the embodiments may be practiced without these specificdetails. For example, well-known circuits, processes, algorithms,structures, and techniques may be shown without unnecessary detail inorder to avoid obscuring the embodiments. It is also the case thatmodules, software, or algorithms can be performed on one server,multiple servers or share the same server. A platform is a major pieceof software, such as an operating system, an operating environment, or arelational database or data store, under with various smallerapplication programs can be designed to run. An operating system is themost important software program running on most computer systems. Itmanages a processors memory, processes, all of the software and programsloaded onto it, and all of the connected hardware. The operatingsystem's job is to manage all of the software and hardware on thecomputer. Most of the time, there are many different software programsoperating at once as well as multiple connected hardware devices. Thereare many operating systems—the most basic is the disk operating systemor “DOS.” Each type of computer or device typically has its owndifferent operating systems. Some typical operating systems are iOS,Windows, Android, and Linux.

The networks disclosed may be implemented in any number of topologies. Anetwork is made of many computing devices that can include computers,servers, mainframe computers, network devices, peripherals, or otherdevice connected together. A network allows these devices to share dataand communicate with each other. The most prominent network is theInternet—that connects billions of devices all over the world. There aremany types of network devices including: computers, consoles, firewalls,hubs, routers, smartphones, switches, wearables, watches, and cameras.Networks are set up in many different ways referred to as networktopologies. Some of the most common topologies include tree, hybrid,ring, mesh star, and bus. The tree topology is the generally usedtopology. A computer is typically an electronic device for storing andprocessing data according to instruction it reads. A console is a textentry and display device. A firewall is network security system, eitherhardware- or software-based, that controls incoming and outgoing networktraffic based on a set of rules, and acts as a barrier between a trustednetwork and other untrusted networks—such as the Internet—orless-trusted networks—a firewall controls access to the resources of anetwork through a positive control model. This means that the onlytraffic allowed onto the network defined in the firewall policy isallowed; all other traffic is denied. A hub is a connection point formultiple devices in a network. A hub typically has multiple ports suchthat if packets of data arrive at one port they are copied to the otherports. A router is a device that forwards data packets along thenetwork. A router connects two or more networks such as an intranet tothe internet. Routers use headers and forwarding tables to determine howdata packets should be sent using certain paths in the network. Thetypical router protocol using ICMP to communicate and configure the bestpath. A network switch is different from a router. Switches serve ascontrollers that enable networked devices to communicate with eachother. Switches create networks while routers connect networks together.

Networks operate on the seven layer Open System Interconnection (OSI)model. The OSI model defines a conceptual networking framework toimplement protocols and divides the task of networking into a verticalstack of the seven layers. In the OSI model, communication control ispassed through the layers from the first to the seventh layer. The firstor “top” layer is the “physical” layer. Layer 1 transmits the bit streamof ones and zeros indicated by electrical impulse, light, or radiofrequency signals—thus providing a method of interacting with actualhardware in a meaningful way. Examples of the physical layer includeEthernet, FDDI, B8ZS, V.35, V.24, and RJ45. The second layer is calledthe Data Link layer. At layer 2 data packets are encoded and decodedinto a bit stream in compliance with transmission protocols that controlflow control and frame synchronization. The Data Link layer 2 isactually a combination of two different layers: the Media Access Control(MAC) layer and the Logical Link Control (LLC) layer. The MAC layercontrols a computer's access to the network. The LLC basically controlsframe synchronization, flow control, and various types of errorcorrection. Examples of the Data Link layer include PPP, FDDI, ATM, IEEE802.5/802.2, IEEE 802.3/802.2, HDLC, and Frame Relay. The third OSIlayer, called the “Network” layer, provides the switching and routingtechnology to create logical paths to transmit data from one node toanother in the network. The Network layer also performs the function ofrouting, forwarding, addressing, internetworking, error handling,congestion control, and packet sequencing. Layer 3 examples includeAppleTalk, DDP, IP, and IPX. The fourth OSI layer is the Transportlayer. Layer 4 provides transparent transfer of data between devices.Layer 4 also performs error recovery and provides flow control forcomplete data transfer. Examples of layer 4 include SPX, TCP, and UDP.OSI layer 5 called the Session layer because it manages and terminatesthe connections between different applications. The Session layercoordinates communication between applications. It sets upcommunications and terminates the communications between applications ateach end—establishing and ending a “session.” Examples include NFS,NetBios, names, RPC, and SQL. Layer 6 is called the Presentation Layer.Layer 6 is really the “transformation” layer—transforming data from thefinal layer to a format the network understands and vice versa. Layer 6formats and encrypts data sent on the network and decrypts the data fromthe network. Examples include ASCII, EBCDIC, TIFF, GIF, PICT, JPEG,MPEG, and MIDI. Finally, the last layer 7, is called the ApplicationLayer. Everything at this layer is specific to applications, and thislayer provides the services for email, file transfers, and other networkapplications. Examples include WWW browsers, NFS, SNMP, FTP, Telnet, andHTTP.

Implementation of the techniques, blocks, steps and means describedabove may be done in various ways. For example, these techniques,blocks, steps and means may be implemented in hardware, software, or acombination thereof. For a hardware implementation, the processing unitsmay be implemented within one or more application specific integratedcircuits (ASICs), complex instruction set computers (CISCs), reducedinstruction set computers (RISCs), advanced RISC machines (ARMs),digital signal processors (DSPs), digital signal processing devices(DSPDs), programmable logic devices (PLDs), field programmable gatearrays (FPGAs), processors, controllers, micro-controllers,microprocessors, other electronic units designed to perform thefunctions described above, and/or a combination thereof. A processor isimplemented in logic circuitry that includes the basic functions of AND,NAND, OR, and NOR functions Functionally, processors are typicallycomposed of RAM as well as address and data buses, the processingcircuitry and accumulators. The busses supply the data and programminginstructions from RAM, ROM, CACHE, or other memory to the processingcircuitry. The speed of a processor depends both on the speed of theprocessing circuitry as well as the speed of the data and address bussesthat supply the circuitry. And the speed of the data and address busesare also gated by the speed of the RAM. It is critical that all of thesecomponents have speeds that are matched to one another to maximizeprocessor performance. Processors use machine level instruction codes tomanipulate data. Other instructions must be compiled to machine levelinstructions to for the processor to perform the operations. Dual coreprocessors have dual processing circuitry and multiple address and databuses.

Also, it is noted that the embodiments may be described as a processwhich is depicted as a flowchart, a flow diagram, a swim diagram, a dataflow diagram, a structure diagram, or a block diagram. Although adepiction may describe the operations as a sequential process, many ofthe operations can be performed in parallel or concurrently. Inaddition, the order of the operations may be re-arranged. A process isterminated when its operations are completed, but could have additionalsteps not included in the figure. A process may correspond to a method,a function, a procedure, a subroutine, a subprogram, etc. When a processcorresponds to a function, its termination corresponds to a return ofthe function to the calling function or the main function.

Furthermore, embodiments may be implemented by hardware, software,scripting languages, firmware, middleware, microcode, hardwaredescription languages, and/or any combination thereof. When implementedin software, firmware, middleware, scripting language, and/or microcode,the program code or code segments to perform the necessary tasks may bestored in a machine readable medium such as a storage medium. A codesegment or machine-executable instruction may represent a procedure, afunction, a subprogram, a program, a routine, a subroutine, a module, asoftware package, a script, a class, or any combination of instructions,data structures, and/or program statements. A code segment may becoupled to another code segment or a hardware circuit by passing and/orreceiving information, data, arguments, parameters, and/or memorycontents. Information, arguments, parameters, data, etc. may be passed,forwarded, or transmitted via any suitable means including memorysharing, message passing, token passing, network transmission, etc.

For a firmware and/or software implementation, the methodologies may beimplemented with modules (e.g., procedures, functions, and so on) thatperform the functions described herein. Any machine-readable mediumtangibly embodying instructions may be used in implementing themethodologies described herein. For example, software codes may bestored in a memory. Memory may be implemented within the processor orexternal to the processor. As used herein the term “memory” refers toany type of long term, short term, volatile, nonvolatile, or otherstorage medium and is not to be limited to any particular type of memoryor number of memories, or type of media upon which memory is stored.

Moreover, as disclosed herein, the term “storage medium” may representone or more memories for storing data, including read only memory (ROM),random access memory (RAM), magnetic RAM, core memory, magnetic diskstorage mediums, optical storage mediums, flash memory devices and/orother machine readable mediums for storing information. The term“machine-readable medium” includes, but is not limited to portable orfixed storage devices, optical storage devices, and/or various otherstorage mediums capable of storing that contain or carry instruction(s)and/or data. Cache memory, also called the central processing unit (CPU)memory, is random access memory that the processor can access morequickly than standard RAM. Cache memory is typically integrated into thecircuitry with the processing unit, but sometimes can be placed on aseparate chip. The principle purpose of cache memory is to store theprogram instruction for the operational software such as an operatingsystems. Most long running software instructions reside in cache memoryif they are accessed often.

While the principles of the disclosure have been described above inconnection with specific apparatuses and methods, it is to be clearlyunderstood that this description is made only by way of example and notas limitation on the scope of the disclosure.

What is claimed is:
 1. A power distribution discovery system for discovering equipment modules comprising: a power source; a power distribution unit comprising: a plurality of outlets coupled to the power source by an electrical cable, each of the plurality of outlets being configured to transfer electrical power from the power source to an equipment module of a plurality of equipment modules, each equipment module of the plurality of equipment modules being positioned in a computing rack and connected to an outlet of the plurality of outlets; a first communication circuit magnetically coupled to the electrical cable, the first communication circuit to transmit communications by causing variations in a magnetic flux of the electrical cable and receiving communications by detecting magnetic flux variations in the electrical cable, wherein the first communication circuit facilitates: communication with a plurality of second communication circuits in each of the plurality of equipment modules, and communication with a computing device; an isolator that receives electrical power from the power source and transfers the electrical power to each of the plurality of outlets, the isolator being configured to: prevent communications to the first communication circuit from being propagated to the power source; and prevent communications from the first communication circuit from being propagated to the power source; one or more data processors; and a non-transitory computer readable storage medium containing instructions that when executed on the one or more data processors, cause the one or more data processors to perform actions including: transmitting, via the first communication circuit and to one or more second communication circuits of the plurality of second communication circuits, a first request for identifying information, the first request including an indication that the identifying information is to be transmitted repeatedly, wherein the first request includes a transmission schedule that indicates when the identifying information is to be transmitted to the first communication circuit; receiving, via the first communication circuit and from the one or more second communication circuits of the plurality of second communication circuits, an identifying information for an equipment module of the plurality of equipment modules, the identifying information being received according to the transmission schedule; preventing, by the isolator, the identifying information from being propagated to the power source; and generating a report that includes the identifying information.
 2. The power distribution discovery system for discovering equipment modules of claim 1, wherein the actions further include sending, via the first communication circuit and to each second communication circuit of the plurality of second communication circuits, a second request for identifying information for a particular equipment module connected to an outlet of the plurality of outlets, the plurality of equipment modules including the particular equipment module.
 3. The power distribution discovery system for discovering equipment modules of claim 1, wherein the first request for identifying information is transmitted at predetermined time intervals.
 4. The power distribution discovery system for discovering equipment modules of claim 1, wherein the first request includes an indication that the identifying information is to be transmitted to the first communication circuit periodically and a time interval that is to elapse between each transmission.
 5. The power distribution discovery system for discovering equipment modules of claim 1, wherein the actions further include: receiving, from the computing device, a request for identifying information; and sending the report to the computing device.
 6. The power distribution discovery system for discovering equipment modules of claim 1, wherein the identifying information is transmitted through an electrical cable that electrically couples the power distribution unit to the equipment modules.
 7. The power distribution discovery system for discovering equipment modules of claim 1, wherein the actions further including: receiving, via the first communication circuit and from the computing device, a request for identifying information from each equipment module of the plurality of equipment modules connected to the power distribution unit, wherein the request is transmitted to one or more other power distribution units; and sending the report to the computing device, wherein the report is configured to be received with one or more other reports from the one or more other power distribution units, and wherein the report and the one or more other reports indicate which equipment modules of the plurality of equipment modules receive power from the power distribution unit and which equipment modules of the plurality of equipment modules receive power from one of the one or more other power distribution units.
 8. A non-transitory, computer-readable medium comprising instructions that, when executed by one or more processors, causes the one or more processors to perform operations to discover equipment modules comprising: transmitting, via a first communication circuit of a power distribution unit and to each second communication circuit of a plurality of second communication circuits of a plurality of equipment modules, a first request for identifying information, the first request including an indication that the identifying information is to be transmitted repeatedly, wherein the first request includes a transmission schedule that indicates when the identifying information is to be transmitted to the first communication circuit, and wherein the first communication circuit is magnetically coupled to an electrical cable that transfers power from a power source, and wherein the first request for identifying information is transmitted by varying a magnetic flux of the electrical cable; receiving, via the first communication circuit of the power distribution unit and from each second communication circuit of the plurality of second communication circuits of the plurality of equipment modules, the identifying information for an equipment module of the plurality of equipment modules, wherein the identifying information is received upon detecting a variation in the magnetic flux of the electrical cable, wherein the identifying information is received according to the transmission schedule, and wherein the power distribution unit comprises: a plurality of outlets coupled to the power source through the electrical cable, each of the plurality of outlets being configured to transfer, from the power source, electrical power to an equipment module of the plurality of equipment modules, each equipment module of the plurality of equipment modules being positioned in a computing rack and connected to an outlet of the plurality of outlets; and an isolator positioned between the power source and the plurality of outlets the isolator being configured to: prevent communications to the first communication circuit from being propagated to the power source; and prevent communications from the first communication circuit from being propagated to the power source; preventing, by the isolator, the identifying information from being propagated to the power source; and generating a report that includes the identifying information.
 9. The non-transitory, computer-readable medium comprising instructions that, when executed by one or more processors, causes the one or more processors to perform operations to discover equipment modules of claim 8, further comprising sending, via the first communication circuit and to each second communication circuit of the plurality of second communication circuits, a second request for identifying information for a particular equipment module connected to an outlet of the plurality of outlets, the plurality of equipment modules including the particular equipment module.
 10. The non-transitory, computer-readable medium comprising instructions that, when executed by one or more processors, causes the one or more processors to perform operations to discover equipment modules of claim 8, wherein the first request for identifying information is transmitted at predetermined time intervals.
 11. The non-transitory, computer-readable medium comprising instructions that, when executed by one or more processors, causes the one or more processors to perform operations to discover equipment modules of claim 8, wherein the first request includes an indication that the identifying information is to be transmitted to the first communication circuit periodically and a time interval that is to elapse between each transmission.
 12. The non-transitory, computer-readable medium comprising instructions that, when executed by one or more processors, causes the one or more processors to perform operations to discover equipment modules of claim 8, further comprising: receiving, from a computing device, a request for identifying information; and sending the report to the computing device.
 13. The non-transitory, computer-readable medium comprising instructions that, when executed by one or more processors, causes the one or more processors to perform operations to discover equipment modules of claim 8, wherein the identifying information is transmitted through an electrical cable that electrically couples the power distribution unit to the equipment modules.
 14. The non-transitory, computer-readable medium comprising instructions that, when executed by one or more processors, causes the one or more processors to perform operations to discover equipment modules of claim 8, wherein the operations further comprising: receiving, via the first communication circuit and from a computing device, a request for identifying information from each equipment module of the plurality of equipment modules connected to the power distribution unit, wherein the request is transmitted to one or more other power distribution units; and sending the report to the computing device, wherein the report is configured to be received with one or more other reports from the one or more other power distribution units, and wherein the report and the one or more other reports indicate which equipment modules of the plurality of equipment modules receive power from the power distribution unit and which equipment modules of the plurality of equipment modules receive power from one of the one or more other power distribution units.
 15. A power distribution discovery method for discovering equipment modules, the method comprising: transmitting, via a first communication circuit of a power distribution unit and to each second communication circuit of a plurality of second communication circuits of a plurality of equipment modules, a first request for identifying information, the first request including an indication that the identifying information is to be transmitted repeatedly, wherein the first request includes a transmission schedule that indicates when the identifying information is to be transmitted to the first communication circuit, and wherein the first communication circuit is magnetically coupled to an electrical cable that transfers power from a power source, and wherein the first request for identifying information is transmitted by varying a magnetic flux of the electrical cable; receiving, via the first communication circuit of the power distribution unit, and from each second communication circuit of the plurality of second communication circuits of the plurality of equipment modules, the identifying information for an equipment module of the plurality of equipment modules, wherein the identifying information is received upon detecting a variation in the magnetic flux of the electrical cable, wherein the identifying information is received according to the transmission schedule, and wherein the power distribution unit comprises: a plurality of outlets coupled to the power source through the electrical cable, each of the plurality of outlets being configured to transfer, from the power source, electrical power to an equipment module of the plurality of equipment modules, each equipment module of the plurality of equipment modules being positioned in a computing rack and connected to an outlet of the plurality of outlets; and an isolator positioned between the power source and the plurality of outlets the isolator being configured to: prevent communications to the first communication circuit from being propagated to the power source; and prevent communications from the first communication circuit from being propagated to the power source; preventing, by the isolator, the identifying information from being propagated to the power source; and generating a report that includes the identifying information.
 16. The power distribution discovery method for discovering equipment modules of claim 15, further comprising sending, via the first communication circuit and to each second communication circuit of the plurality of second communication circuits, a second request for identifying information for a particular equipment module connected to an outlet of the plurality of outlets, the plurality of equipment modules including the particular equipment module.
 17. The power distribution discovery method for discovering equipment modules of claim 15, wherein the first request for identifying information is transmitted at predetermined time intervals.
 18. The power distribution discovery method for discovering equipment modules of claim 15, wherein the first request includes an indication that the identifying information is to be transmitted to the first communication circuit periodically and a time interval that is to elapse between each transmission.
 19. The power distribution discovery method for discovering equipment modules of claim 15, further comprising: receiving, from a computing device, a request for identifying information; and sending the report to the computing device.
 20. The power distribution discovery method for discovering equipment modules of claim 15, further comprising: receiving, via the first communication circuit and from a computing device, a request for identifying information from each equipment module of the plurality of equipment modules connected to the power distribution unit, wherein the request is transmitted to one or more other power distribution units; and sending the report to the computing device, wherein the report is configured to be received with one or more other reports from the one or more other power distribution units, and wherein the report and the one or more other reports indicate which equipment modules of the plurality of equipment modules receive power from the power distribution unit and which equipment modules of the plurality of equipment modules receive power from one of the one or more other power distribution units. 